Orbital lathe



W. F. GROENE Aug. 8, 1933.

ORBITAL LATHE Filed Nov. 18, 1929 3 Sheets-Sheet 1 ATTORN EY W. F.GROENE Aug. 8, 1933.

ORB I TAL LATHE Filed Nov. 18, 1929 5 Sheets-Sheet 2 Lara 4 ai m ATTOR NEY W. F. GROENE Aug. 8, 1933.

ORBITAL LATHE Filed Nov. 18, 1929 S Sheets-Sheet 5 R v l o a. BY vATTORN EY Patented Aug. 8, 1933 UNITED STATES ORBITAL LATHE William F.Grocne, Cincinnati, Ohio, assignor to The R. K. Le Blond Machine ToolCompany, Cincinnati, Ohio, a Corporation of Delaware ApplicationNovember 18, 1929 Serial No. 407,814

9 Claims. (Cl. 82-9) My invention relates to machine tools such aslathes, and more particularly to the performance of machining andcutting operations performed on a piece of work which is moving duringthe operations thereon in an orbital path. In the structure shown myinvention is applied to a crank shaft lathe in which crank pins are outwhile the crank shaft is being rotated upon its bearings.

In an application for patent Serial No. 246,314, filed Jan. 12, 1928 bymyself and Harold F. Siekmann, there is shown and described a crankshaft lathe for a similar purpose to the one illus trated herein forthat construction, there were frames which moved in eccentric paths andthere were tools in the several frames for operating on two sides of acrank pin at once. The tools were provided with feeding devices, one foreach frame, the particular mechanisms including fluid pressure cylindersand rack and pinion mechanism mounted on each frame and connected to amaster device.

In my present improvement I employ frames mounted and moved in eccentricpaths, but provide for the tool feed by bodily movingone of the sets ofeccentrics which impart the work following movement to the entire groupof frames thereby feeding the frames that carry the tools as a group, toand from the work.

Certain features illustrated in this application and some parts of themachine which have not been illustrated but are referred to are found inthe Groene and Siekmann application above referred to in my applicationSer. No. 283,712 filed June 7, 1928 for Steady rests; Ser. No. 297,881filed Aug. 6, 1928 for Chucking devices; and Ser. No. 159,448 filed Jan.6, 1927 for Air chucks.

In my present machine there is a flexibility to the working structurewhere called for and a high degree to resistance to distorting forceswhich housings being tied together at their tops by tie bar 3 in thefront, and by tie bar 4, in the rear.

A power shaft 5 extends across the lower part of the bed from side toside and beyond. On each end, outside the bed is mounted pinion gears 6,and as shown in Fig. 3, to the left-the shaft 5 extends beyond thepinion 6, thus providing for a power application, as a motor, to drivethe machine.

The side frames 2 are provided with bifurcated or pocketed portions 7,as. shown in Fig. 3, formed by integral webs in the housings of theframe, these web portions carrying bearings 8, one on each side housing.Journaled in the bearings are pins 9 having journal extensions 10.Pivotally mounted on the pins'9 are arms 11a of a feed frame 11 whichfeed frame carries at its upper forward ends, bearings 12.

The base 1, at each side towards the rear, has a bearing 13 formed in itand mounted in thesehearings is a master crankshaft 14, this shafthaving ends extending beyond the bearing. The eccentrics 14a on thisshaft match the path of the pins of a crank shaft to be turned. A secondmaster crankshaft 15 is mounted in the bearings 12 of the feed frame 11,and has extend ends similar to master crankshaft 14. This shaft also haseccentrics which match the movement of the pins of the crankshaft thatconstitutes the work. I

Mounted in the side housings 2 at their forward part are a pair ofcrankshaft chucks 16, these chucks being similar to those shown in myheretofore mentioned pending applications; the spindles of these chucksprovide for the mounting of driving means.

Mounted on the master shaft 14 extensions at each end, are driving gears16a shown in Figs. 1 and 2 by dotted pitch lines and in full lines inFig. 3-, these gears 16a meshing with the pinions 6 on the power shaft5. The master shaft 15, has mounted on its extensions, driving gears 17and the crankshaft chucks also have mounted on their spindles thedriving gears 18. w

The extension journals 10 of the pins 9 have mounted on them idler gears19. The idler gears mesh with gears 16, 17 and 18 of the mastercrankshafts and the chucks and thus form a complete drive-at each endfor the master'shafts and the chucks from the source ofpower. As will benoted the center of movement of the frame 11 is co-axial with that ofthe idlers 19, so that the gears 17 'move in a planetary path about theidlers when the frame is moved.

A series of spacer frames 20 are mounted on the bed by bolts 21a, thesespacer frames being seated at their tops in notches 21 in the tie bars 3and 4, the notches being wider than the frames 20 so that by means ofadjusting screws 22, the frames 20 can be shifted sidewise slightly intoperfect alinement with contiguous parts.

The spacer frames 20 also carry, at their front edge, extensionspreferably serving as steady rests for the line bearings of a crankshaftwhere such rests are necessary.

At a point near the side housings are located thrust frames23, theseframes being similar to spacer frames 20 except that they need carry noextensions for steady rest purposes, their purpose being to offerresistance to thrusts from operating parts mounted between them and thespacer frames.

The thrust frames have, on their side toward the center of the lathe attheir front and rear edges, fastened hardened steel rub plates 24.

The spacer frames 20 and also the tool frames to be described have onthe front and rear edges of both their sides hardened steel rub plates 2these plates providing a long wearing, friction reducing, bearingsurface for the tool frames, spacer frames and thrust plates 23.

In the spaces left between the thrust and the spacer frames are mountedthe tool carrying frames 26, these frames at their lower'part havebearings 27, which are mounted on the eccentrics of the lowermastercrankshaft 14. On the eccentrics of the upper master crankshaftare mounted strap arms 27a having at their outer ends pin bearings 28.Pins 29 in these bearings serve to mount bifurcated arms 30, said armshaving on one side the half bearings 31. n the upper front edges of thefeeding frames 26 are located the half bearings 32.

The extensions of the bifurcated arms 30 are drilled for bolts 33, asare the upper front edges of the feeding frames 26, these bolt holesbeing each side of the half bearings in the two members. The pins 34,which are located in the two half bearings, 31 and 32, completes thetool frame assemblies and provide a slightly self -adjusting connectionfor the feeding frames to the two master shafts when one of the shaftsis moved to the rear as will be explained later.

When one or the other of the bolts 33 is tightened or loosened, a finesize adjustment of the tool is obtained, and thereafter beingpermanently locked in position by the two bolts 33. When the feedingframe is in the position of turning the pin of a crankshaft, theeccentric driving of the tool frames is the same as if the strap arms27a were bolted to, or a rigid part of, the feeding frame structures.

The particular machine illustrated is designed for an eight cylinderengine crankshaft and therefore requires three'steady rests for the linebearings. These steady rests are the same as shown in my application nowpending, as noted in an earlier part of this specification and consistsof a hinged top clamping member 34a, a hinged pressure member 35, awedge member 36 and a fluid pressure cylinder 37 to actuate the wedge.When the clamp is closed and valve 38 is operated and thus admittingpressure to the cylinder, the wedge member 36 is moved downward, rockingthe pressure member 35 against the clamp thus holding it closed untilthe turning of the crankshaft is finished, whereupon the valve is againoperated and the clamp released thus permitting it to be opened and theshaft removed.

As in the Greene and Siekmann application, the arrangement of theeccentric shafts is such as to leave the front of the machine free forinsertion or withdrawal of the work. i

A recess 39 is located in base of the macnin at its center and extendingfrom the rear almost to the front. Mounted in this recess is a fluidpressure cylinder 40, having a piston 41 and piston rod 42, this rodhaving an extending portion with the upper half cut away for part of itslength .and having a rack piece 43 fastened to the cutaway portion. Theextended portion of the rod rides in a bearing 44 formed as part of abracket 45, this, bracket having its upper part formed as a pair ofbearings 46. Mounted on a shaft 4'7 in this bearing is a toothedquadrant 43, this toothed quadrant having a portion extended to form anear for a bearing 49. Mounted on a pin in bearing 49, is a bifurcatedadjustable link 50, this link terminating in a bearing at its upper end.

At the center of the lower rear edge of feed frame 11, is formed a pairof ears or lugs 51 having bearings for a pin or shaft, 52. The upperbearing end of link 50 is placed between the ears 51 and pin 52 insertedthus completing an operative organization for rocking the feed frame andwith it the upper master crankshaft and tool feeding frames. When theframes are thus moved the tools themselves move through part of the arcof a circle to and away from the work.

Provision is made for fluid connection to the cylinder 40 by conduits 53in the bracket 45, these conduits leading the fluid to opposite ends ofthe cylinder and controlled by the usual type valves for admission andexhaust.

With the piston 41 and its parts as shown in Fig. 1 (the pin turningposition) if pressure fluid be admitted to the cylinder at the endfarthest from the front of the machine the piston and its stem and rack43 will move toward the opposite end of the cylinder and revolve thetoothed quadrant 48 to the left (looking at Fig. 2) causing the link torock the feed frame 11, on pins 9 as a pivot to the right, thus carryingthe upper master crankshaft to the right and rocking the tool feedframes to the right on the master crankshaft 14, as a pivot.

It is to be noticed in Fig. 2 that there are a. pair of stops 54, in theside housings 2, and stops 55, in the feed frameto engage the stops 54.When these stops are in contact the tools 58, have reached a point wherethey are turning a true circle or may be said to be in the finishingposition for the pins of a crankshaft.

In order to explain the operation of the device I have drawn lines 56and 5'7-Figs. 1 and 2, which lines indicate the direction of coactingeccentrics on the master shafts 14 and 15. It is to be noted in Fig. 1that these lines are parallel so that the eccentrics are workingtogether. is only when these two centers of both the master crankshaftand their eccentrics. are parallel that the tools then cut a truecircle. Looking now at f 140 Q Fig. 2 wherein the feed frame 11 has beenrocked on pins 9 to its most rearward position and the gears 1'7 therebyrevolved which is the position when the tools 58 are farthest away fromthe eccentric. In such a position the two eccentrics are not workingtogether, because while they are alike to each other and move incomplete synchronism, the upper one is'in a different orbital positionfrom the lower. With the eccentrics so placed the movement of the toolwill be an ellipse.

Each coacting eccentric, of course, maintains the same relative angle,as the upper master shaft is swung and hence slightly rocked due to thegearing connection.

When now the frame 11 is rocked forwardly as it is during the feedingstroke, the points of the tools describe an elliptical path, thiselliptical path gradually changing to a true circle as the angle ofeccentricity of the upper eccentrics approaches the angle of the lowereccentrics, which is the position shown in Fig. 1.

This period of the feed of the tools, wherein the tools are traveling intowards the pin in a gradually decreasing elliptical orbit is used toface the cheeks of the webs 60 of the crankshaft 59, shown mounted inthe chucks 16 and the steady-rests on the spacer frames 20.

As the tool approaches the pin of the shaft 59, the path of the toolsbecomes more circular and the cutting action on the cheek faces is moreand more a turning action until when the close vicinity of the pin ofthe shaft is reached, the path of the tool is, to all intents andpurposes, a true circular path which becomes absolute as the pin isturned to its finished diameter.

While by providing for a differential gear drive to the two masters, achain or idlergear method of keeping the masters in parallel wouldaccomplish a part of the objects of my invention, it is an advantage tohave the working movement of the tool have an elliptical path and end upwith a circular path. On other jobs of work it might be of value to forman elliptical surface by reversing the" arrangement described, since themasters can be so set as to synchronize with each other at any selectedpoint of the planetary movement of the movable one.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:--

1. In a machine tool requiring an orbital tool movement, a work holder,a series of tool holders, a masters having a series of throws of theorbital movement required, means for supporting the tool holders so asto move with the throws of said masters, and means for moving one firstmaster to and from the work, thus accomplishing a feed for the tools onthe holders, the last named means comprising a frame in which movablemaster is supported and driving means for the movable master centered atthe axis of move ment of the frame, said tool holders being pivotallyengaged with cranks on the movable master.

2. In an orbital lathe, the combination with a frame of means thereonfor engaging and rotating a crank shaft on its axis so that the crankpins move in an eccentric path, a series of tool carrier members spacedfrom each other, tools mounted on said carriers, means for moving saidcarriers eccentrically with the crank pins, and

spacing means between the adjacent carriers,

said carriers and spacing means being held tightly together to preventdeviation of the tools incident to the necessary running fit of thecarriers on the means for moving them.

3. In an orbital lathe, the combination with a frame of means thereonfor engaging and rotating a crankshaft on its axis so that the crankpins move in an eccentric path, a series of carrier members spaced fromeach other,- tools mounted on said carriers, and spacing means mountedon the frame and lying between the spaced carrier members and in bearingengagement therewith, and forming a solid metallic mass across thelathe.

, 4. In an orbital lathe, means for supporting and rotating a crankshaft of which the pins are to be operated upon, a movable frame,eccentric means rotating in the frame in synchronism with the crankshaft rotating means, tool carrying frames mounted on said eccentricmeans and moved thereby, said tool carrying frames being spaced apartfrom each other, and spacing means mounted in the lathe and lyingbetween the spaced carrier members and in bearing engagement therewithand forming a solid metallic mass across the lathe.

5. In an orbital lathe, a tool holder, a work holder, means for movingthe tool holder in the orbital path required by the work, a fluidpressure motive device, a rack actuated by said motive device, a segmentactuated by said rack, having an arm, and a pitman connecting said armwith said tool holder, said tool holder being pivoted for movement bysaid pitman to feed the tools to and from the work, while said toolsfollow the orbital path.

6. In an orbital lathe, a frame, a work holder and a master memberrotatably mounted in said frame, a second master member, a feedingmember supporting the second master member for rotation therein andmovably connected to said frame intermediate of the master members, atool holder supported on the first master member and articulatelyconnected to the second master member for movement by said mastermembers orbitally to the work holder, and means for rotating the workholder and the master members in synchronism.

7. In an orbital lathe, a frame, a work holder and a master memberrotatably mounted in said frame, a second master member, a feedingmember supporting the second master member and pivoted to rock on saidframe intermediate of the master members, a tool holder supported on thefirst master member and articulately connected to -the second mastermember for movement by the master members orbitally to the work holder,and means for rotating the work holder and the master members insynchronism, comprising an intermediate transmission member rotatable onthe axis of rocking of said feeding member.

8. In an orbital lathe, a rotatable work holder and a rotatable mastermember operatively connected for synchronous rotation and relativelyrockable, a tool carried by the master member orbitally to the workholder and fed by the relative rocking, said relative rocking permittingthe synchronous rotation for circular orbital movement of the toolconcentric with the work holder at only one stage of the relativerocking, and means abutting together to positively stop the relativerocking at said stage.

9. In an orbital lathe, a rotatable work holder, a rotatable mastermember operatively connected to said work holder for synchronousrotation therewith and rockable relatively thereto, a tool carried bythe master member orbitally to the work holder and fed by the rocking ofthe master member, said rocking permitting the synchronous rotation forcircular orbital movement of the tool concentric with the work holder atonly one stage of said rocking, and means'abutting together topositively stop said rocking at said stage.

WILLIAM F. GROENE.

